About Circu.ioPlay new game Circu.io for free online at our website iogames.nu. You can play this game in your browser and your mobile for free. As we know, Circu is an incredibly simple game that challenges the players reaction speed and compares it to other players in the match. After a short amount of time red balls will appear on the screen, the person who clicks them the fastest wins the round.
Use your left mouse button to click the red circles.